256-Channel Analog Front End (AFE) for Digital X-Ray, Flat-Panel Detectors


Recommended alternative parts

  • AFE1256  - The device has SIMILAR FUNCTIONALITY but is not functionally equivalent to the compared device.   The AFE2256 is lower power, has wider input charge range, and faster than the AFE1256

More Information

Full data sheet and other design resources are available under NDA. Request now


The AFE2256 is a 256-channel, analog front-end (AFE) designed to suit the requirements of flat-panel detector (FPD)-based digital x-ray systems. The device includes 256 integrators , a programmable gain amplifier (PGA) for full-scale charge level selection, a correlated double sampler (CDS) with dual banking, and 256:4 analog multiplexers.

The device also features four 16-bit successive-approximation register (SAR) analog-to-digital converters (ADCs). Serial data from the ADCs are available in low-voltage differential signaling (LVDS) format.

The Nap and power-down modes enable substantial power saving that is especially useful in battery-powered systems.

To request a full datasheet or other design resources: request AFE2256


  • 256 Channels
  • On-Chip, 16-Bit ADC
  • Photodiode Short Immunity
  • High Performance:
    • Noise: 750 Electrons RMS
      (1.2-pC Input Charge Range)
    • Low Correlated Noise
    • Integral Nonlinearity:
      ±2 LSB with Internal 16-Bit ADC
    • Scan Time:
      • < 20 µs to 204.8 µs
  • Integration:
    • Six Selectable, Full-Scale Input Ranges:
      0.6 pC (Min) to 9.6 pC (Max)
    • Internal Timing Generator (TG)
    • Built-In Correlated Double Sampler
    • Pipelined Integrate and Read for Improved
      Throughput: Allows Data Read During
    • Serial LVDS Output
  • Simple Power-Supply Scheme:
    • AVDD1 = 1.85 V
    • AVDD2 = 3.3 V
  • Low Power Consumption
  • Nap and Total Power-Down Mode
  • Custom Chip-On-Film (COF) Packages

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Parametrics Compare all products in Photodiode Sensing

# Input Channels
Resolution (Bits)
Package Group
Operating Temperature Range (C)
Package Size: mm2:W x L (PKG)
AFE2256 AFE0064
256    64   
16    14   
SPI/LVDS    N/A   
COF    LQFP   
Catalog    Catalog   
0 to 85    -40 to 85   
320COF: 1064 mm2: 28 x 38(COF)    128LQFP: 256 mm2: 16 x 16(LQFP)   
Internal Reference Buffer
Nap Mode
Power Down
Differential Outputs
Internal Reference Buffer
Nap Mode
Power Down